Using the clecoed left wing as a reference again, I continued to dimple the right wing parts prior to priming.
These include the
- Upper flange on all but the 4 most inboard wing ribs (except the holes that attach to the main spar)
- Lower flange on the 2nd and 3rd inboard most wing ribs (except the holes that attach to the main spar)
- The flap hinge rib holes that attach to the skins (expect for the inboard most flap hinge rib holes that attach to the top skin)
- Remaining holes in the rear spar top flange
- Top skin J-channel stiffeners
- Torque tube bracket flanges
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| Rib flanges dimpled as described in the plans, with the exception of also dimpling the holes along the bottom of the second and third inboard most ribs (because those are easier to dimple now) |
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| Rear spar upper flange fully dimpled (except for holes that were previously countersunk) |
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| Skin stiffeners dimpled and ready for priming |
These were all dimpled using the DRDT-2 and pneumatic squeezer, however I again ran across a few gotchas for which I came up with the following solutions
- For the rear spar top flange dimpling, I used the same masking tape technique as described in a prior post to avoid scratches.
- Be sure not to dimple the two holes of the inboard most flap hinge rib that attach to the top skin. The top skin is countersunk at these locations for the wing walk doublers, so these rib holes do not require dimpling.
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| Important to mark holes that should not be dimpled to avoid unintentional dimpling! |
- I used the narrow 3/32" female dimple die to dimple the J-channel stiffeners to ensure there was no interference with the bend.
- Even though the plans don't call out dimpling any lower rib flange holes at this time, I decided to dimple all skin attach holes on the flap hinge ribs, as well as the lower flange holes on the 2nd and 3rd inboard most ribs as there will be very little room to get a squeezer into those locations once the ribs are installed. Having reviewed the Bottom Wing Skin section of the plans this should not be an issue since all holes are already final sized.
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| Flap hinge ribs dimpled on top and bottom flanges where required |
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| Dimpled torque tube bracket flanges |
Prior to dimpling the top skins, I tackled the scarf joint where the two skins overlap at the main spar. I followed the RV-14 plans as suggested in the
RV-10 wiki because the explanation of the intended end result is much easier to visualize than what is shown in the RV-10 plans. I first set up some test pieces to practice with and figure out the best technique for sanding the surface.
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| Getting ready to practice filing skin corners by first practicing on some scrap |
After some trial with different files, I found that the medium files pictured above, along with the
10" flat curved tooth file worked best for material removal and control of filing.
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| Practice results look good! |
When the test pieces were laid over each other, the combined thickness of the sheets was about 0.040" all the way across. That's the most I felt comfortable in terms of filing the sheet thickness down, as I wanted to avoid a knife edge while still having perfectly acceptable results when the tank skin was placed against the wing skins.
With the practice out of the way, I attempted to replicate the same results on the actual skins. Clamping down each skin, I spent around 20 minutes filing each corner and was very happy with the results. I finished off the corners by carefully deburring the hole edges within the filed area.
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| Skin clamped to table and non-filed area masked off for protection |
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| Results of filing first skin corner. Looks good! |
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| Edge view of skin after filing. I filed down to a minimum thickness of about 0.01" |
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| Final outboard skin corner filed and finished with a Scotchbrite pad |
The only thing left to do prior to priming all parts was to dimple all skin holes that had rivet callouts. Fairing, wing tip attachment and countersunk holes were taped off to avoid any dimpling errors, and I made sure enough space was available on my workbenches to ensure I had room to maneuver the long outboard skins.
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| Outer top skin supported across both workbenches while dimpling |
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| Aft nutplate holes were dimpled using the pneumatic squeezer. The #8 screw hole was dimpled first, followed by the nutplate attach holes using a narrow 3/32" female dimple die |
Prior to dimpling the forward row of skin holes, I also decided to use the edge forming tool on the lower edge of the skin that attaches to the main spar. This will ensure a tight fit. I did not edge form the overlapping skin edges as the skin bends slightly along the rib, and I did not want to cause any issues with that edge puckering out due to being creased by edge forming. Maybe it wouldn't be an issue, but I'll leave that edge as is.
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| Dimpled holes at the filed corners. No issues with dimple cracking! |
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| Outboard top skins fully dimpled |
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| Inboard top skins fully dimpled |
All that was left prior to priming was to finish match drilling the holes in the outboard left wing rib for the aileron attach bracket.
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| Left wing outboard rib match drilled for outboard aileron attach bracket |
Build Hints
- Mark or tape off any holes that should not be countersunk and/or dimpled. This helps avoid errors as you get into a rhythm of modifying holes.
- RV-14 plans had a much better description of how to create the scarf joints between skins. The skin was easy to file down gradually. Just take time and make sure the skin is adequately clamped down prior to filing.
- Dimpling the outboard top skins requires a large maneuvering area, and moving supports around as the skin is positioned under the dimpler.
- A narrow diameter female dimple die is very useful for dimpling nutplate attach holes next to dimpled screw holes due to limited space between the attach holes and the screw hole.
Dates: February 1 - February 11 2024
Top Wing Skins Total Time: 22.0 hours
RV-10 Build Total Time: 604.1 hours
Priming Total Time: 50.9 hours (not included in build time totals)
